DE102013105481A1 - Expansion of pipes - Google Patents

Abstract

The invention relates to an expansion system and a method for expanding tubes (R). The expansion system contains an expansion tool (110) with a typically hollow cylindrical elastomeric pressure body (111), which is arranged between a tie rod (124) and a cover (123). The pressure element (111) can be axially compressed and the tube can thus be expanded by screwing an adjusting element (122) on a tie rod (121), which connects the tie rod (124) and the cover (123). The pipe expansion is preferably limited by a two-part or multi-part outer shape (150).

Description

The invention relates to an expansion tool for pipes, an outer mold for use in pipe expansion, an expansion system, a pipe joint, and a method for expanding a pipe.

From the EP 2 153 917 A2 For example, methods for expanding a tube are known in which an elastomeric body inserted into the tube end is used. A hydraulic fluid, which is pumped into the interior of the elastomer, thereby causing the desired expansion of the tube.

Against this background, it was an object of the present invention to provide means for simple and reliable pipe expansion.

This object is achieved by a flaring tool according to claim 1, by an outer mold according to claim 6, by an expansion system according to claim 8, by a method according to claim 9, and by a pipe joint according to claim 10. Advantageous embodiments are contained in the subclaims.

• a) Einen Zuganker, der beim Gebrauch des Aufweitwerkzeuges im Rohr anzuordnen ist. Der Durchmesser des Zugankers bestimmt somit, welche Rohre (mit welchem Innendurchmesser) durch das Werkzeug bearbeitbar sind.
• b) Einen dem Zuganker funktionell zugeordneten zweiten Körper, welcher nachfolgend als "Deckel" bezeichnet wird. Beim Einsatz des Aufweitwerkzeuges wird der Deckel in der Regel zumindest teilweise außerhalb des Rohres angeordnet, insbesondere so, dass er sich an dem Rohr bzw. an dessen Stirnseite abstützen kann. Der Deckel wird daher typischerweise einen größeren Durchmesser als der Zuganker und als das zu bearbeitende Rohr haben. Grundsätzlich sind jedoch auch Ausführungsformen im Rahmen der Erfindung eingeschlossen, bei denen der Deckel ähnlich wie der Zuganker innerhalb des Rohres angeordnet werden kann.
• c) Eine Zugstange, welche den Zuganker und den Deckel koppelt. Die Kopplung beinhaltet dabei insbesondere eine Kopplung in Bezug auf Zugkräfte, die zwischen Zuganker und Deckel wirken.
• d) Zugmittel zur Aufbringung einer Zugkraft auf die Zugstange derart, dass der Abstand zwischen Zuganker und Deckel verändert werden kann (zumindest in einer Richtung, vorzugsweise in Richtung einer Verkürzung).
• e) Einen elastisch verformbaren Druckkörper, welcher zwischen Zuganker und Deckel angeordnet ist.

According to a first aspect, the invention relates to an expansion tool for pipes, wherein the term "pipe" in the context of the present application is to be understood to mean all components or components which have a tubular or sleeve-shaped section (with a circular or any cross section) , Thus, in addition to tubes in the narrower sense, this may also be, for example, a fitting which has a cylindrical ("tubular") fitting. The expansion tool contains the following components:

• a) A tie rod, which is to be arranged in the pipe when using the expansion tool. The diameter of the tie rod thus determines which tubes (with which inner diameter) are machinable by the tool.
• b) a second body, which is functionally assigned to the tie rod, which is referred to below as "cover". When using the expansion tool, the cover is usually arranged at least partially outside the tube, in particular so that it can be supported on the tube or on its end face. The lid will therefore typically have a larger diameter than the tie rod and as the pipe to be machined. In principle, however, embodiments are included within the scope of the invention, in which the lid can be arranged similar to the tie rod within the tube.
• c) A tie rod coupling the tie rod and the cover. The coupling includes in particular a coupling in relation to tensile forces acting between tie rods and cover.
• d) traction means for applying a tensile force on the tie rod such that the distance between the tie rod and cover can be changed (at least in one direction, preferably in the direction of a shortening).
• e) An elastically deformable pressure body, which is arranged between tie rods and cover.

The expansion tool has the advantage that with a mechanical tensile force the deformable pressure body between the tie rod and cover can be compressed so that it provides by its radial evasive movement for a widening of a surrounding tube.

The pull rod may preferably have a thread or a similar device. Components of the traction means can then couple in a simple manner force-transmitting to the tie rod.

In a further development of the above embodiment, the traction means may consist wholly or partly of a control body, which engages in the thread of the pull rod so that the distance between the tie rod and cover can be changed by its rotation. The "rotation" of the actuating body is to be understood as a relative rotation between the actuating body and tie rod, d. H. relative to the environment or to the pipe, the actuator body, the tie rod, and / or both can rotate. The thread of the tie rod is typically an external thread in this case.

The actuator can be identical in principle with the tie rod or the lid. Advantageously, however, the adjusting body is a separate component, which is supported on the lid, and preferably on the side facing away from the tie rod of the lid. By a screwing movement of the actuating body along the pull rod, the cover is then moved toward the tie rod. Such a control element may be formed, for example, similar to a threaded nut. In particular, the adjusting body can have points of attack or surfaces for a tool, for example key surfaces for the attachment of a wrench.

The pull rod can be rotatably or rotatably coupled to the tie rod and / or with the lid. Advantageously, the connection is such that, during a widening process, tie rods and covers do not perform any rotational movements relative to the tube. The same applies preferably also for the drawbar.

The elastically deformable pressure body is preferably (almost) incompressible, that is, it practically does not change its volume under pressure. It may in particular be an elastomer or contain such. The elastomer may in particular be a rubber with polyurethane. The Shore A hardness of the elastomer is preferably between 80 and 95 ( DIN 53505 ), its tensile strength preferably between 34 N / mm ² and 45 N / mm ² ( DIN 53504 ).

Suitable elastomers are, in particular, "dry elastomers" which do not liquefy or change their structure even under high pressure. Furthermore, the elastomer should be temperature resistant (e.g., in a range of about -60 ° C to 70 ° C) as well as oil and solvent resistant.

The geometric shape of the pressure hull can vary within wide ranges. Preferably, the pressure body is hollow cylindrical. In this case, the pull rod can pass through the hollow interior of the pressure hull, while tie rods and covers rest on the end faces of the hollow cylinder.

In a further embodiment of the invention, the traction means on a hydraulic cylinder, by means of which the tie rod can be moved. In this way it can be avoided that the tensile forces must be applied by hand.

Said hydraulic cylinder can optionally have a hydraulically movable punch which can be (reversibly) coupled to the drawbar in order to transmit tensile force thereto. The hydraulic fluid can then be kept away from the other facilities of Aufweitwerkzeuges, in particular of the parts to be arranged in the pipe. The connection of the hydraulic cylinder can be done for example via a coupling piece, are screwed into the punch and pull rod.

According to a second aspect, the invention relates to an outer shape for limiting tube expansions, which consists of at least two interconnectable parts.

The outer mold may be used in pipe expansion to provide a stop to the radial expansion of a pipe and thereby avoid damage to the pipe (e.g., cracks). The outer mold typically has a passage (inner opening) in which a tube to be expanded can be arranged, wherein the tube rests at least partially on the inner wall of the passage after the expansion process. According to the invention, such an outer shape should be composed of at least two parts, the parts only resulting together in the required passage. Due to the multi-part, the application of the outer shape to a pipe to be machined is greatly simplified.

According to a preferred embodiment, the parts of the outer mold are designed so that each of them surrounds an associated pipe by a maximum of half the pipe circumference. The parts can therefore be easily applied from the side to a pipe or be removed from a widened pipe again. In the simplest case, the outer shape can be formed by two parts, which are designed, for example, half-shell-shaped and each individually surround a tube only by 180 °.

A firm connection between the parts of the outer mold can be achieved in various ways, for example by screwing the parts together, or by the slipping of retaining rings. Preferably, the parts of the outer mold are identical to one another and / or formed mirror-inverted.

Furthermore, the invention relates to an expansion system for pipes, which includes a widening tool for widening the pipe and an outer shape of the type described above. The expansion tool may in particular be a widening tool according to the present invention. Other widening tools are for example from the EP 2 153 917 A2 known.

By replacing the tie rod, the tie rod, the cover, the pressure hull and / or the outer shape, the expansion system according to the invention can be easily adapted to all pipe diameters as needed.

• a) Die Anordnung eines elastisch verformbaren Druckkörpers im Rohr zwischen einem im Rohr befindlichen Zuganker und einem (innerhalb oder außerhalb des Rohres befindlichen) Deckel, wobei Zuganker und Deckel durch eine Zugstange gekoppelt sind.
• b) Die Verkürzung des Abstandes zwischen Zuganker und Deckel, beispielsweise durch Schrauben eines Stellkörpers relativ zur Zugstange.

According to a fourth aspect, the invention relates to a method for expanding a tube, which comprises the following steps:

• a) The arrangement of an elastically deformable pressure hull in the pipe between a tie rod located in the pipe and a (located inside or outside of the pipe) cover, tie rods and lid are coupled by a tie rod.
• b) The shortening of the distance between tie rod and cover, for example by screwing a control element relative to the drawbar.

The method can be carried out in particular with a widening tool or a widening system of the type described above. It covers in general terms the steps that can be performed with such a widening tool. Explanations given for the expansion tool therefore apply analogously to the method and vice versa.

The method may optionally include as an additional step the placement of the tube to be expanded in an outer shape to limit the expansion. The outer shape may in particular consist of several parts as described above.

It should be noted that the expansion system and the method can also be used for calibrating the pipe wall thickness. In this case, the expansion of the inner diameter of the tube may be of minor importance, while it is paramount that after completion of the expansion process, a defined thickness of the tube wall is present and any tolerances are balanced. Of course, an expansion and a calibration can also be sought and achieved simultaneously.

• – Einem Rohr mit einer Aufweitung, insbesondere der Aufweitung eines Endes des Rohres.
• – Eine Stützhülse mit einem Endstück, welches in der Aufweitung des Rohres angeordnet ist.
• – Eine die Aufweitung (und gegebenenfalls andere Teile des Rohres) zumindest teilweise umgebende Außenhülse, wobei in die Außenhülse mindestens eine Einschnürung zur Pressverbindung von Außenhülse, Rohr und Stützhülse eingearbeitet ist.

According to a fourth aspect, the invention relates to a pipe joint with the following components:

• - A tube with a widening, in particular the widening of one end of the tube.
• - A support sleeve with an end piece, which is arranged in the expansion of the tube.
• - An outer sleeve at least partially surrounding the expansion (and possibly other parts of the tube), wherein in the outer sleeve at least one constriction for press-connection of outer sleeve, tube and support sleeve is incorporated.

Said constriction detected as deformation in addition to the outer sleeve preferably also the tube and possibly also the support sleeve. The constriction may in particular have been produced by a roll pressing method, as described for example in US Pat EP 1 186 820 B1 . DE 102 43 706 C1 , or EP 2 500 140 A2 is described. The widening of the tube has preferably been produced in the tube connection by the method according to the invention.

In all embodiments of the invention, the tube may be wholly or at least partially made of metal (e.g., copper, steel, stainless steel, aluminum or mixtures thereof), or it may be made of plastic. In particular, it can be a composite tube consisting of layers of different materials (for example, plastic and metal). Particularly preferably, it is a composite tube, in which a metal tube is surrounded inside and outside by a plastic tube or a plastic layer.

The (outer) diameter of the machined pipes is today usually up to about 140 mm, with composite pipes up to about 120 mm, and can be even larger in the future. The wall thickness of the tubes, depending on the tube diameter and tube type (e.g., PEX, composite tube, etc.), is typically from about 1.5mm to about 4mm, to about 7.5mm, to about 10mm, or to about 15mm. However, it can be edited with appropriate design of the devices and larger pipe diameter or wall thicknesses.

In the following, exemplary embodiments of the invention will be explained in more detail with reference to the figures, wherein identical or similar parts of different embodiments bear reference numerals which differ by multiples of 100. It shows:

1 a perspective view of a first embodiment of a Aufweitwerkzeuges invention;

2 a sectional view of a first expansion system according to the invention after arrangement on a pipe and before the beginning of the expansion process;

3 the expansion system of 2 after completion of the expansion process;

4 an exploded view of a second expansion system according to the invention with a screw of the outer mold;

5 a sectional view through the expansion system of 4 after completion of the expansion process;

6 a perspective view of a third expansion system according to the invention with a hydraulic cylinder;

7 an exploded view of the expansion system of 6 ;

8th a pipe joint according to the invention with a flared pipe;

9 a pipe joint without flared pipe;

10 a composite pipe according to a preferred embodiment of the invention.

• – einen Zuganker 124;
• – einen elastomeren Druckkörper 111;
• – einen Deckel 123;
• – einen Stellkörper, hier in Form einer Mutter 122;
• – eine Zugstange 121.

1 shows in a perspective view a widening tool 110 according to a first embodiment of the present invention. This contains the following components:

• - a tie rod 124 ;
• - An elastomeric pressure body 111 ;
• - a lid 123 ;
• - A control body, here in the form of a mother 122 ;
• - a drawbar 121 ,

Like from the 2 and 3 is recognizable, is the elastomeric pressure body 111 a hollow cylinder, which of the drawbar 121 is penetrated. The drawbar coupled in this way the tie rod 124 with the lid 123 , The pull rod has (at least at one end) on its outside a thread G, in which the nut 122 intervenes.

2 shows in a sectional view the arrangement of the expansion tool 110 in a pipe R, for example a plastic pipe. The outer diameter of the pressure hull 111 corresponds essentially to the inner diameter of the tube to be expanded R. Furthermore, the diameter of the tie rod 124 smaller than the inner diameter of the tube R, so that the tie rod fits into the tube. The diameter of the lid 123 on the other hand, it is larger than the pipe diameter, so that the cover can be supported on the end face of the pipe.

Furthermore, in 2 an outer shape 150 recognizable, which surrounds the dilated end of the tube. The outer shape has a passage which corresponds to the outer contour of the tube R to be produced and which serves as a boundary for the expansion process. The outer shape 150 consists of two parts or half shells 151a . 151b which are connectable to each other or separable from each other. In this way, the outer shape can easily put around a pipe or remove it from a widened pipe again. Optionally, more than two parts can be provided.

The connection of the parts of the outer shape 150 with each other, for example, about screws 152 happen. In the example shown connect the screws 152 the outer mold parts 151a . 151b with the lid 123 the Aufweitwerkzeuges and thereby ensure a connection of the half shells with each other.

If the mother 122 continue on the thread G of the drawbar 121 is screwed, it pulls the pull rod in the pulling direction z out of the tube R. As in 3 can be seen, this is the tie rod 124 in the direction of the lid 123 moved, whereby the pressure element located between tie rod and cover 111 is compressed in the axial direction. Since the volume of this pressure body is substantially constant, this reacts with a radial expansion, which causes the desired deformation (expansion) of the tube R.

The 4 and 5 show a second embodiment of an expansion system according to the invention 200 with a widening tool 210 and an outer shape 250 , The expansion tool 210 corresponds essentially to that of 1 - 3 and will therefore not be explained again in detail.

The outer shape 250 consists of two (eg mirror-image) half-shells 251a and 251b , These are directly connected by tangential screws 252 in tapped holes 253 intervention.

How out 5 is recognizable, has the outer shape 250 at its front end an inner circumferential groove, in which the mushroom-shaped head of the lid 223 of the expansion tool 210 intervenes. As a result, a fixed coupling between the outer shape 250 and expansion tool 210 reached.

In the 6 and 7 is a third embodiment of an expansion system according to the invention 300 shown. Both the expansion tool 310 as well as the outer shape 350 This system can essentially be similar to the solutions described above. However, the pulling force on the drawbar 321 not applied via a nut or the like, but by a hydraulic cylinder 330 ,

The hydraulic cylinder 330 has an oil connection 332 on which hydraulic oil can be pumped into an internal chamber or pumped out of it. This allows a stamp 331 controlled move in the pulling direction.

The Stamp 331 can via a coupling piece 333 mechanically with the drawbar 321 be coupled so that he moves this. For example, the coupling piece 333 have an internal thread, which is based on corresponding external thread of drawbar 321 and stamp 331 screw it on. An advantage of this solution is that no hydraulic fluid gets inside the tube to be expanded.

8th shows in a sectional view a pipe connection, as it can be produced with a tube R according to the invention expanded. In the pipe connection, the end piece FE of a (eg metallic) support sleeve F is arranged in the widened part of the pipe R. On the outside, the expanded pipe end is surrounded by a (eg metallic) outer sleeve H. Furthermore, there are one or more annular circumferential constrictions E which have been worked in place on the outer sleeve to press outer sleeve H, tube R, and support sleeve F together. Such constrictions can be produced, for example, by a rolling operation, as shown in the EP 2 500 140 A2 is described.

9 shows a corresponding pipe connection when using a non-expanded tube R '. In this pipe joint results in a cross-sectional constriction in the region of the support sleeve F, while in the in 4 shown pipe connection, the inner diameter of the conduit can remain substantially constant.

• – einer äußeren Kunststoffbeschichtung bzw. einem Kunststoffmantel P1, die beispielsweise aus Polyethylen ("PEX") besteht;
• – einem mittleren Metallrohr M, das beispielsweise aus Aluminium, Kupfer, Stahl und/oder Edelstahl besteht;
• – einer inneren Kunststoffbeschichtung bzw. -rohr P2, die beispielsweise ebenfalls aus Polyethylen ("PEX") besteht.

The tubes in the preceding examples may, for example, be (in particular thin-walled) metal tubes or plastic tubes. In particular, however, it may also be composite pipes, one of which in 10 is shown in more detail. The composite pipe R of 10 consists of three layers or layers, namely:

• - An outer plastic coating or a plastic sheath P1, which consists for example of polyethylene ("PEX");
• A central metal tube M made of, for example, aluminum, copper, steel and / or stainless steel;
• - An inner plastic coating or tube P2, which is also made of polyethylene ("PEX"), for example.

When expanding composite pipes with conventional expansion heads ("spreaders"), it is easy to detach the inner (plastic) layer from the metal layer at the edges of the individual expansion bodies. Such problems are avoided with the approach or tool according to the invention, so that they should preferably be used in composite pipes.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2153917 A2 [0002, 0020]
• EP 1186820 B1 [0027]
• DE 10243706 C1 [0027]
• EP 2500140 A2 [0027, 0053]

Cited non-patent literature

• DIN 53505 [0011]
• DIN 53504 [0011]

Claims (10)

Expansion tool ( 110 . 210 . 310 ) for tubes (R), comprising: a) a tie rod to be arranged in the tube ( 124 . 224 . 324 ); b) a lid ( 123 . 223 . 323 ); c) a pull rod ( 121 . 221 . 321 ), which tie rod and cover coupled; d) a traction device ( 122 . 222 . 330 ) for applying a tensile force to the drawbar, so that the distance between the tie rod and cover can be changed; e) an elastically deformable pressure body ( 111 . 211 . 311 ), which is arranged between tie rods and cover. Expansion tool ( 110 . 210 . 310 ) according to at least one of the other claims, characterized in that the drawbar ( 121 . 221 . 321 ) has a thread (G). Expansion tool ( 110 . 210 ) according to claim 2, characterized in that the traction means an actuating body ( 122 . 222 ), which engages in the thread (G) of the pull rod so that the distance between the tie rod and cover can be changed by its rotation. Expansion tool ( 110 . 210 . 310 ) according to at least one of the other claims, characterized in that the pressure body ( 111 . 211 . 311 ) is or contains an elastomer, preferably a polyurethane rubber. Expansion tool ( 310 ) according to at least one of the other claims, characterized in that the traction means a hydraulic cylinder ( 330 ) having. Outer shape ( 150 . 250 . 350 ) for limiting tube expansions, characterized in that they consist of at least two parts ( 151a . 151b ; 251a . 251b ; 351a . 351b ) consists. Outer shape ( 150 . 250 . 350 ) according to claim 6, characterized in that each of the parts ( 151a . 151b ; 251a . 251b ; 351a . 351 b ) an associated pipe (R) surrounds at most half of the pipe circumference. Expansion system ( 100 . 200 . 300 ) for tubes (R), comprising: - a widening tool ( 110 ), preferably according to any one of claims 1-5; - an outer shape ( 150 . 250 . 350 ) according to one of claims 6 or 7. Method for expanding a pipe (R), comprising the steps of: a) arranging an elastically deformable pressure body ( 111 . 211 . 311 ) in the pipe between a tie rod located in the pipe ( 124 . 224 . 324 ) and a lid ( 123 . 223 . 323 ), with tie rod and cover by a pull rod ( 121 . 221 . 321 ) are coupled; b) reduction of the distance between tie rod and cover, preferably by screwing a setting body ( 122 ) relative to the drawbar.  Pipe connection containing: - A pipe (R) with a widening, in particular a composite pipe made of metal and plastic; - A support sleeve (F) with an end piece (FE), which is arranged in the expansion of the tube; An outer sleeve (H) surrounding the expansion, wherein in the outer sleeve at least one constriction (E) for the press connection of outer sleeve, tube and support sleeve is incorporated.

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